I bought my box set of the entire series in late 2009, I was reading through some old threads and noticed people complaining that season 3 had been heavilly tampered with.

It seems to me most of the issues are not present on my DVD's.

Lost Knight seems fine, the sound effects have been restored during the backpack scene.

Dead Of Knight seems fine other than the Billy Idol song at the start of the episode is a cover version, but that may have been the case anyway. When Doves Cry has been removed and the girl is dancing to silence however this is due to liscencing issues. The same is true of the Laura Branigan song in Halloween Knight's opening scene, but again this may have been a cover originally too.

Knight Of The Chameleon seems to be the way I remembered it.

I watched Junk Yard Dog last night and the music was restored in the teaser clip.

The only thing I can think of is that Knights Of The Fast Lane seems to be missing the microlock sound effect in the final car chase scene.

I'm guessing they fixed the issues and moving forward provided the new ones for the box sets. I have the black box set with the red scanner on the front.

Do you have the US version box or EU version? I have bought three different EU region 3rd Season DVD releases (UK, Nordic and Nordic slim case) and all of them have missing sound effects. Haven't bought the entire 1-4 box though, just the one Season per box releases.